The Large Magellanic Cloud and the Distance Scale

The Magellanic Clouds, especially the Large Magellanic Cloud, are places where multiple distance indicators can be compared with each other in a straight-forward manner at considerable precision. We here review the distances derived from Cepheids, Red Variables, RR Lyraes, Red Clump Stars and Eclipsing Binaries, and show that the results from these distance indicators generally agree to within their errors, and the distance modulus to the Large Magellanic Cloud appears to be defined to 3% with a mean value of 18.48 mag, corresponding to 49.7 Kpc. The utility of the Magellanic Clouds in constructing and testing the distance scale will remain as we move into the era of Gaia.Comment: 23 pages, accepted for publication in Astrophysics and Space Science. From a presentation at the conference The Fundamental Cosmic Distance Scale: State of the Art and the Gaia Perspective, Naples, May 201

Desempenho de pontas de pulverização em Brachiaria brizantha cv. MG-4 para controle de ninfas de cigarrinhas das pastagens Spray nozzles performance in Brachiaria brizantha cv. MG-4 for pastures spittlebugs nymphs control

O trabalho teve como objetivo estudar o desempenho de pontas de pulverização na deposição da calda inseticida para o controle de ninfas de cigarrinhas das pastagens em Brachiaria brizantha cv. MG-4. Doze tratamentos foram estudados em esquema fatorial 6x2, constituídos pelo contraste de seis pontas de pulverização e pressões de 196 e 392 kPa: TF-VP2 (336 L ha-1 e 467 L ha-1); AI11002-VS (184 L ha-1 e 200 L ha-1); XR11002-VS (200 L ha-1 e 280 L ha-1); TT11002-VP (200 L ha-1 e 280 L ha-1); TJ60-11002VS (208 L ha-1 e 280 L ha-1) e TX-VK4 (72 L ha-1 e 97 L ha-1). Para monitorar a deposição das caldas de pulverização, utilizaram-se os traçadores Azul Brilhante FD&C-1 (0,3% p/v) e Amarelo de Tartrasina FD&C-5 (0,6% p/v). Alvos artificiais, constituídos de lâminas de vidro, foram posicionados na base das plantas, próximos à superfície do solo, e os depósitos por unidade de área das soluções pulverizadas foram quantificados por espectrofotometria. As pontas TF-VP2, XR11002-VS e AI11002-VS, nas pressões de 196 e 392 kPa, proporcionam as maiores deposições da calda de pulverização na região das espumas das cigarrinhas das pastagens, apesar de apresentarem menor uniformidade na distribuição dos depósitos em relação a TX-VK4, XR110.02-VS e TJ110.02-VS. O aumento da pressão de 196 para 392 kPa promoveu aumento na deposição da calda de pulverização sobre a Brachiaria brizantha e na região onde se encontram as espumas das cigarrinhas para todos os tipos de pontas estudadas.<br>The work aimed to study spray nozzles performance in pesticide sprayer deposition for controlling pastures spittlebugs nymphs in Brachiaria brizantha cv. MG-4 pasture. Twelve treatments were studied in factorial scheme 6x2, constituted by the contrast of six spray nozzles and 196 and 392 kPa work pressures: TF-VP2 (336 L ha-1 and 467 L ha-1); AI11002-VS (184 L ha-1 and 200 L ha-1); XR11002-VS (200 L ha-1 and 280 L ha-1); TT11002-VP (200 L ha-1 and 280 L ha¹); TJ60-11002VS (208 L ha-1 and 280 L ha-1) and TX-VK4 (72 L ha-1 and 97 L ha-1). For monitoring sprayer deposition it was used Bright Blue FD&C-1 (0.3% p/v) and Tartrasine Yellow FD&C-5 (0.6% p/v) as tracers. Artificial targets, constituted by thin glass plates were positioned on plants tillers base, near to soil surface and deposition per unit area of sprayed solutions were quantified by spectrophotometry. TF-VP2; XR11002-VS and AI11002-VS spray nozzles, in 196 and 392 kPa work pressures provided the largest sprayer deposition in the foam regions of pastures spittlebugs nymph, in spite of showing inferior uniformities of sprayer deposition in relation to TX-VK4, XR110.02-VS and TJ110.02-VS.The increase of work pressure from 196 to 392 kPa promoted the increase of sprayer deposition over Brachiaria brizantha and over the region where pastures spittlebugs foams were located for all types of spray nozzles studied